1. Algebra 2 Honors Unit 7
Ways to collect data

2. Ways to collect Data:
Observational study: researcher observes and records measurements of variables of interest but does not impose a treatment
EX: A town councilman decides to close down all ice cream parlors because the crime rate in his town has been significantly higher whenever ice cream sales were higher.

3. Ways to collect Data:
Sample survey: a study in which subjects are asked a question or series of questions
EX: Asking 100 students from each grade level how they feel about the school lunches

4. Ways to collect Data:
Experiment: applies a treatment to experimental units to observe an effect.
EX: A medical researcher wanted to determine the effect of a new drug on a specific type of cancer. He recruited 50 female and 50 male cancer patients, each diagnosed with this specific cancer that had progressed to the same stage. The anticipated effect of the drug was a 50% reduction in the size of the tumor within 4 weeks of treatment. All subjects would receive an injection, but some would receive the drug and others would receive a placebo.

5. What is it? Sample survey, Experiment, or Observational study?
A group of researchers combed their hair or put on make-up at one of the available sinks while they watched and recorded if people washed their hands or not after going the bathroom.
The psychology department at a university asks a group of graduates on how they perceived the value of their education.
A group of students was selected to test the effectiveness of a new study technique. Some of the students were asked to study in a quiet room while eating mint lifesavers. The other students were asked to study in a quiet room and could not eat anything. All students were given a test over the material they studied and their scores were recorded.
Observational study
Sample Survey
Experiment

6. Partner chat!
For each of the following scenarios determine whether a sample survey, observational study, or experiment would be best. EXPLAIN YOUR ANSWER. We will discuss as a group in a few minutes.
What percentage of teenagers leave the water running when they brush their teeth?
Which of two drugs is more effective at preventing nausea following the onset of a migraine?
Do male or female teenagers tend to have more numbers stored in their cell phones?
What percent of drivers come to a complete stop at a stop sign near a local elementary school?
Does printing suggested tip amounts on the bottom of a restaurant bill increase the average amount that customers leave in tips?

7. Blue Eye Brown Eye Experiment
Clips 1:30 – 5:48
6:55 -

8. Controversial Experiments
The Stanford Prison Experiment
The Milgram “Shock Experiments”
Explain the study and why it was controversial
Name a different (more ethical) way that the researchers could have collected their data and come to a conclusion.